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Source/Engine/GraphicsDevice/OpenGL/GPUTimerQueryOGL.cpp

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+// Copyright (c) 2012-2020 Wojciech Figat. All rights reserved.
+
+#if GRAPHICS_API_OPENGL
+
+#include "GPUTimerQueryOGL.h"
+#include "RenderToolsOGL.h"
+
+GPUTimerQueryOGL::GPUTimerQueryOGL(GPUDeviceOGL* device)
+	: GPUResourceOGL<GPUTimerQuery>(device, String::Empty)
+{
+	GLuint queries[2];
+	glGenQueries(2, queries);
+	VALIDATE_OPENGL_RESULT();
+
+	_startQuery = queries[0];
+	_endQuery = queries[1];
+
+	// Set non-zero mem usage (fake)
+	_memoryUsage = sizeof(queries);
+}
+
+GPUTimerQueryOGL::~GPUTimerQueryOGL()
+{
+	ReleaseGPU();
+}
+
+void GPUTimerQueryOGL::ReleaseGPU()
+{
+	if (_memoryUsage == 0)
+		return;
+
+	GLuint queries[2];
+	queries[0] = _startQuery;
+	queries[1] = _endQuery;
+
+	glDeleteQueries(2, queries);
+	VALIDATE_OPENGL_RESULT();
+
+	_memoryUsage = 0;
+}
+
+void GPUTimerQueryOGL::Begin()
+{
+	glQueryCounter(_startQuery, GL_TIMESTAMP);
+	VALIDATE_OPENGL_RESULT();
+
+	_endCalled = false;
+}
+
+void GPUTimerQueryOGL::End()
+{
+	if (_endCalled)
+		return;
+
+	glQueryCounter(_endQuery, GL_TIMESTAMP);
+	VALIDATE_OPENGL_RESULT();
+
+	_endCalled = true;
+	_finalized = false;
+}
+
+bool GPUTimerQueryOGL::HasResult()
+{
+	if (!_endCalled)
+		return false;
+
+	GLint done = 0;
+	glGetQueryObjectiv(_endQuery, GL_QUERY_RESULT_AVAILABLE, &done);
+	VALIDATE_OPENGL_RESULT();
+
+	return done == GL_TRUE;
+}
+
+float GPUTimerQueryOGL::GetResult()
+{
+	if (!_finalized)
+	{
+#if BUILD_DEBUG
+		ASSERT(HasResult());
+#endif
+
+		GLuint64 timeStart;
+		GLuint64 timeEnd;
+
+		glGetQueryObjectui64v(_startQuery, GL_QUERY_RESULT, &timeStart);
+		VALIDATE_OPENGL_RESULT();
+
+		glGetQueryObjectui64v(_endQuery, GL_QUERY_RESULT, &timeEnd);
+		VALIDATE_OPENGL_RESULT();
+
+		_timeDelta = (timeEnd - timeStart) / 1000000.0f;
+
+		_finalized = true;
+	}
+	return _timeDelta;
+}
+
+#endif